Rotating Stars in Relativity

TL;DR

This paper reviews the latest theoretical developments in the study of rotating relativistic stars, including their equilibrium properties, oscillations, instabilities, and applications in modified gravity and numerical relativity.

Contribution

It provides an updated comprehensive review of rotating stars in relativity, covering new theories, universal relations, instabilities, and numerical studies.

Findings

Updated sections on equilibrium and oscillations.

New insights into instabilities and universal relationships.

Numerical relativity applications including hydrodynamics and magnetohydrodynamics.

Abstract

Rotating relativistic stars have been studied extensively in recent years, both theoretically and observationally, because of the information they might yield about the equation of state of matter at extremely high densities and because they are considered to be promising sources of gravitational waves. The latest theoretical understanding of rotating stars in relativity is reviewed in this updated article. The sections on equilibrium properties and on nonaxisymmetric oscillations and instabilities in $f$-modes and $r$-modes have been updated. Several new sections have been added on equilibria in modified theories of gravity, approximate universal relationships, the one-arm spiral instability, on analytic solutions for the exterior spacetime, rotating stars in LMXBs, rotating strange stars, and on rotating stars in numerical relativity including both hydrodynamic and magnetohydrodynamic studies of these objects.